White Rice Consumption is a Risk Factor for Metabolic Syndrome in Tehrani Adults: A Prospective Approach in Tehran Lipid and Glucose Study

Background: Consumption of white rice has been proposed as a dietary risk factor for development of metabolic disorders and type 2 diabetes, especially in populations who consume white rice as a staple food. In this study, we investigated the association between consumption of white rice and the occurrence of metabolic syndrome in Tehrani adults after 3 years of follow-up. Methods: This longitudinal study was conducted within the framework of the Tehran Lipid and Glucose Study on 1476 adults, aged 19-70 years. Dietary intakes were measured using a validated semi-quantitative food frequency questionnaire at baseline. Biochemical and anthropometric measurements were assessed and documented at baseline (2006-2008) and again 3 years later (2009-2011). Multiple logistic regression models were used to estimate the occurrence of the MetS in each quartile of white rice consumption. Results: The mean age of participants was 37.8 +/- 12.3 years, and mean BMI was 26.0 +/- 4.5 Kg/m(2) at baseline. Participants in the highest quartile of white rice consumption were significantly younger, had lower HDL-C levels, and higher systolic and diastolic blood pressures at baseline (P < 0.01). Higher consumption of white rice was also accompanied by higher increase in serum triglyceride levels after the 3-year follow-up (9.9 +/- 2.3 vs. 8.2 +/- 2.3%, P < 0.01). After adjustment for all potential confounders, the risk of metabolic syndrome in the highest quartile of white rice consumption compared with the lowest, was 1.66 (95% CI: 1.04-2.66). Moreover, participants with central obesity, low physical activity or low-fiber diet had greater risk of metabolic syndrome if white rice constituted >= 25.6% of total energy. Conclusion: We demonstrated that higher consumption of white rice may be a risk factor for development of metabolic syndrome among Iranian adults.